The present invention relates generally to the field of vehicle access systems, and more particularly to drive mechanisms for deploying and stowing a transfer member of a vehicle access system.
There are many types of drive mechanisms known to deploy and stow ramps, lift platforms and other transfer members that provide wheelchair access to vehicles. One type of drive mechanism is described in U.S. Pat. No. 6,102,648 to Fretwell et al. Another example is provided in U.S. Pat. No. 5,393,192 to Hall et al.
While various drive mechanisms for extending and retracting transfer members from vehicles are known, there remains a need for improvements in the art. For example, there remains a need for improved vehicle access systems that deploy and stow the transfer member while also maintaining its alignment. There also remains a need for vehicle access systems that allow a transfer member to be manually stowed while maintaining alignment of the transfer member within its frame. Furthermore, there is a need for vehicle access systems that employ multiple drive assemblies for deploying and stowing a transfer member in both automatic and manual modes. The present invention is directed towards meeting these needs, among others.